<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>打印金字塔</title>
	</head>
	<body>
		<script>
			var n=prompt("请输入金字塔层数：");
			document.write('<p align="center">');
             for (var i=1;i<=n;i++) {
                for(var j=1;j<=2*i-1;j++){
                   document.write("*");
                 }
                 document.write("</br>");
      		    }
             
			
		</script>
	</body>
</html>
